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Symptoms: I saw so many transaction timeout stacks in my trace (below). In the meanwhile, I got thread hung and operation unavailable on the WebSphere Application Server (WAS) admin console: [10/8/15 15:45:04:969 IST] 0000003e ThreadMonitor W WSVR0605W: Thread "Default : 9" (000000a2) has been active for 629861 milliseconds and may be hung. There is/are 1 thread(s) in total in the server that may be hung. at java.net.SocketInputStream.socketRead0(Native... [More]

I've been working on some PMRs (Problem Records) lately for threads either completing slowly or being reported as "may be hung" in WebSphere Application Server and many of the products that run on it. A very common scenario is seeing threads in socketRead: For example: [9/15/14 9:32:13:492 PDT] 00000023 ThreadMonitor W WSVR0605W: Thread "WebContainer : 0" (00000021) has been active for 692481 milliseconds and may be hung. There is/are 1 thread(s) in total in the server that may be hung. at... [More]

A common cause of hung threads in WebSphere Application Server is when a thread sends a request to a backend server, such as a database, and waits an unexpectedly long time for a response. When this occurs, you will see socketRead() at the top of the thread's stack trace. For example: [9/8/15 19:19:27:702 EDT] 00000062 ThreadMonitor W WSVR0605W: Thread "WebContainer : 2301" (00001785) has been active for 1425013 milliseconds and may be hung. There is/are 21 thread(s) in total in the server that may be hung. at... [More]

During your Business Process Manager (BPM) development, you may frequently use the web service integration component to invoke an external web service and handle the response back from the web service provider. You may sometimes meet the situation that the discover, type generation, or operation selection very be very slow in Process Designer, sometimes it might even be unresponsive, like below: You may also see the type generation hung like below: This article describes some ways to walk through all possibilities that may... [More]

I wanted to list some steps below to help Identify a High CPU or possible Hang condition in WebSphere Application Server on AIX resulting from non-thread safe HashMap usage. The Hashmap APIs contributing to High CPU or Hung Threads at the top of the java ™ stack, can include removeEntry(), getEntry() or findNonNullKeyEntry() function calls. * Note that this issue can prevail on any OS platform and that the naming convention for the files shown below does vary. 1) Collect the Performance Hang High CPU MustGather data with WebSphere... [More]

Introduction: During the course of WebSphere Application Server operation, a JVM may produce important diagnostic information in a variety of files and formats. In this blog entry, we will briefly examine each of these files and their purpose. A wealth of valuable Java™ virtual machine diagnostic data can be gathered by doing the following tasks: 1) JVM process standard error stream In WebSphere, JVM writes some errors messages on the standard error stream for the JVM process and the file name is... [More]

Sometimes when developing a flow we find that the flow becomes non-responsive. This can be caused by a few different reasons but one of the most common is that the flow is stuck in a logic loop. This can be caused by poor code design or design of the flow itself. Even after identifying and fixing the logic within the flow, you are still stuck with the task of replacing the deployed flow within the Broker. WebSphere Message Broker has built in recovery measures. This means, if the Broker detects that the EG has crashed or stopped unexpectedly,... [More]